Before airplanes and satellite phones, polar exploration was a more dangerous undertaking than it is now. A new article in American Scientist retraces Nansen and Shackleton's expeditions from the perspective of modern ocean conditions and sea ice drift conditions.

Starting this month, a giant NASA DC-8 aircraft loaded with geophysical instruments and scientists will buzz at low level over the coasts of West Antarctica, where ice sheets are collapsing at a pace far beyond what scientists expected a few years ago.

Deep in the Antarctic interior, buried under thousands of meters (more than two miles) of ice, lies Lake Vostok, the world's largest subglacial lake. Scientists believe that the waters of Lake Vostok have not been disturbed for hundreds of thousands of years, and there are tantalizing clues that microbes, isolated for at least as long, may exist.